Unless otherwise indicated herein, the materials described in this section are not prior art to the claims and are not admitted to be prior art by inclusion in this section.
In order to provide user equipment devices (UEs) with access to communicate on a packet-switched network such as the Internet, a wireless service provider may implement a radio access network that is configured to serve the UEs over an air interface and that is coupled with a packet gateway providing connectivity between the RAN and the packet-switched network. When a UE operates within coverage of the RAN, the RAN may work with the UE and the packet gateway to establish one or more bearers for carrying various types of communication traffic between the UE and the packet gateway. Further, the packet gateway or another entity may assign to the UE an Internet Protocol (IP) address for use by the UE to engage in communications on the packet-switched network.
With this arrangement, the UE may then conveniently communicate with entities on the packet-switched network. In particular, the UE may generate packets having headers that specify the UE's assigned IP address as source address and that specify desired destination IP addresses and having payload carrying application-layer content, and the UE may transmit those packets over an appropriate bearer to the packet gateway. Upon receipt of those packets, the packet gateway may then output those packets onto the packet-switched network to be routed to the indicated destination address. Likewise, when packets are transmitted on the packet-switched network to the IP address assigned to the UE, those packets may be routed to the packet gateway (e.g., as a care-of destination for the UE's assigned IP address), and the packet gateway may then transmit those packets over an appropriate bearer to the UE.
Through this process, for example, a UE that supports voice-over-IP (VoIP) communication may conveniently work to set up and engage in VoIP calls, through communication with a VoIP call server (e.g., call control server and media server or media gateway) on the packet-switched network. For instance, if a user of the UE dials a telephone number of a called party, the UE may responsively generate and transmit to the call server a packet-based call initiation message, such as a Session Initiation Protocol (SIP) “INVITE” message designating the called telephone number. The call server and UE may then engage in further call initiation signaling, such as additional SIP signaling, to facilitate setup of a real-time packet-based media session such as a Real-time Transport Protocol (RTP) session between the call server and the UE, and the call server may work to establish connectivity with the called telephone number via the public switched telephone network (PSTN) or similarly through VoIP. With the real-time media session in place between the UE and the call server, and the call connected from the call server to the called party, the UE may then carry on the call with the called party.
In certain implementations, special bearers may be used for this VoIP setup signaling and communication process. For instance, when the UE first registers with the RAN, the RAN may set up a default VoIP signaling bearer for the UE, to be used for SIP signaling to set up VoIP calls. Further, then the UE seeks to initiate a VoIP call, the UE may then further work with the RAN to cause the RAN to establish for the UE a dedicated VoIP bearer for use to carry the real-time voice media between the UE and the call server. The dedicated VoIP bearer may have a defined service level such as a guaranteed bit rate, to help ensure quality voice communication to and from the UE.